Polymer film with optically controlled form and actuation

A low power laser beam is used to induce large and fast variations in the shape of a polymer film due to photoinduced contraction and expansion of the polymer film surface subject to the beam. The direction of the photoinduced bend or twist of the polymer can be reversed by changing the polarization of the beam. Thus the film orientation could be varied within +/- 70 degrees. The phenomenon is a result of optically induced reorientation of azobenzene moieties in the polymer network. (c) 2005 Optical Society of America.